This application claims the priority of Germany Application No. 10045312.0 filed Sep. 12, 2000, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a press as well as a process for transforming work pieces.
A press with a safety shutdown is known from DE 197 01 282 A1 where the drive of the tappet is disengaged by means of a coupling apparatus which receives a signal from a monitoring apparatus if the force exerted upon the tappet deviates from a specified standard value by more than a specified amount. Among other things, it can also be provided with this press that the monitoring apparatus shuts down one or more extractors.
But it is not indicated in this document how this shutdown of the extractor is to be undertaken. It is, however, unambiguous that the shutdown can only be undertaken in connection with shutting down the tappet and consequently can only be undertaken only when a disturbance arises in the area of the tappet.
It is the object of the present invention to create a press for transforming work pieces where in the event of a disturbance in the area of the extractor elements, damage to the extractor elements of the entire press are avoided.
Through at least one measuring sensor which in accordance with the invention is arranged within the lever linkage, the force acting upon at least one extractor element is measured, owing to which at any point in time there is a monitoring on the sequence of the extraction process.
In this way, the triggering apparatus of the invention having the measuring sensor can then disengage the coupling if the height of the force measured deviates from a standard force value specified at a certain point of the motion of the extractor element by a specific amount. In this way, in the event of a disturbance in the area of at least one extractor element, the drive apparatus is disconnected from the extractor element, and the extractor element is shut down. In this way, damage to the extractor element or the entire press can be avoided in cases in which disturbances arise in the region of the extractor element.
Through the process of the invention for transforming work pieces, it is possible to shut down the extractor element already before reaching a maximal force, since already when a certain tolerance is exceeded, that is, a recognizable tendency toward higher emerging forces, the flow of power between the drive apparatus and the extractor element is interrupted.
In an advantageous refinement of the process of the invention, the possibility offers itself of undertaking an adaptation of the force standard values for each operating point in connection with changes of the force acting from the drive apparatus on the extractor element which can arise owing to the shape of the lever linkage. Here the functions of the force or the path of the drive apparatus traversed and the extractor element are adapted to each other, which can be designated as xe2x80x9cdynamization.xe2x80x9d